First, it is possible to use internal or external number range for supplier in SRM. If you are using bbpgetvd to replicate a vendor, you have to choose 'only transfer R/3 numbers' to have ECC vendor number in SRM. If you are using bbp_vendor_sync or would like to have default number range as R/3 number, please check customizing 'Define Global Settings' (Settings for Supplier Synchronization) to maintain only transfer R/3 numbers.

For table VENMAP, it will only show ECC vendor number and SRM vendor GUID (not SRM vendor number). If you would like to check the vendor number mapping, please check table BBPV_BUPA_VENMAP.

For the vendors which are already replicated with wrong number range, you have to delete them and replicate them again.